Railroad yards generally have manually and/or automatically operated switching devices for switching railroad cars from one track to another. These switching devices are well known in the art and have been described for example, in U.S. Pat. Nos. 3,652,849 and 4,337,914 both incorporated by reference herein and made a part hereof.
Generally, a pair of stationery rails and a pair of switching rails are arranged so that the switching rails can be moved to keep trains on a main track or divert them to a branch track. The switching rails are moved by a switching device which includes a connecting rod that extends beneath the tracks to connections with the switching rails.
The switching devices typically include a switch stand to one side of the rails which can be operated either manually or automatically. When operated by hand, the switch is moved to a switch point by throwing a lever arm 180 degrees. For example, in the prior art, a weighted lever arm lying horizontally on the ground or at the base of the switch stand is lifted and thrown 180 degrees to the opposite side of the switch stand where it rests again horizontally on the ground or base. The weight and horizontal position of the lever arm prevents bouncing and accidental repositioning of the switch which could cause derailment. However, due to the large arc of throwing the lever arm and the amount of force and bending over required to carry out this operation, many switchmen have experienced back compression and resulting back and leg injuries. In U.S. Ser. No. 08/268,478, filed Jun. 30, 1994 by the same inventor named herein and assigned to the same entity, a switch stand is disclosed in which a lever arm is rotated less than 180 degrees to effect switching.
Other prior art switch stands have used hydraulic cylinders to effect switching. However, the hydraulic fluid of such cylinders tends to thicken during cold weather, thus tending to make the hydraulic cylinder slow to move, or, in the worst case, locking the cylinder such that no movement occurs.